Geissele Super Duty Upper Receiver Group 14.5" Mk16 Black, MOD 1

ships from our shop in 3 to 5 days (+/-)
Product Discontinued:
No longer offered for sale

Geissele Super Duty Upper Mod 1 Receiver Group 14.5" Black 5.56mm, complete

with the wonderfully mated new unified Mk16 rail and upper receiver, pinned and welded to 16"

The 14.5” complete upper in 5.56mm features a Black anodized upper receiver mated to a unique Mk16 MLOK rail also in Black.  The barrel is 14.5”  Phosphated, Cold Hammer Forged Geissele, Chrome Lined with a 1-7 twist, with nano-coated HUXWRX flash hider, a Geissele low profile bomb-proof factory installed gas block and Geissele's Enhanced BCG.

This is a Geissele Factory upper. For the gun owner looking to build an AR-15 from the ground up with maximum performance-enhancing features, this fully assembled upper receiver from Geissele is a perfect compliment. Geissele Automatics has been a leader in AR-15 products and accessories for years, offering excellent quality and rugged dependability to the war fighter, competitors, and defender alike.

The barrels are precision machined and cold hammer forged in-house. The Mod 1 features a mid-length gas system is perfect for the 14.5" barrel, and includes a Geissele gas Block installed at the factory with both lower set screws and a through the barrel pin.  This is something Geissele has been doing since 2018.  Is it necessary? No.  Extra protection from a gas block moving, which was never going to move in the first place, but something about the Geissele name has that German sound to it, that causes the entire firm to over-engineer, like Mercedes.

The newly designed Super Modular Rail MK16 mates to the upper via a center aligning tab removing any chance of rail rotation. This rail is a variant of the 13.5” SMR MK16, currently fielded by USASOC, and one of Geissele's bestsellers and best ideas.  At Charlie's, we like the way in which the upper mates to the rail, which also is a crutch to better align the rail and upper receiver.  That is a good thing.

The Geissele REBCG is Nano-coated for lubricity and superior protection from the elements.  The Reliability Enhanced BCG is DLC coated in what Geissele calls "Nanocoating" and is machined from mil-spec 8620 steel, with a properly torqued and staked, chrome lined gas key. The REBCG also features extended upper rails, providing greater stability and dramatically increasing feeding reliability. The REBCG is properly torqued and staked, chrome lined gas key. The Cam Pin is machined from advanced, medical steel known as H13 which is also coated with Nanoweapon for maximum corrosion and wear resistance. The Geissele Reliability Enhanced Bolt Carrier Group also features extended upper rails, providing greater stability and dramatically increasing feeding reliability.

The Geissele Reliability Enhanced Bolt Carrier Group comes with the Geissele Stressproof Bolt. Made from Carpenter 158+, directly developed with Carpenter Steel metallurgists to create a material that is cleaner and has less impurities. This makes our Stressproof bolt stronger and more fatigue resistant. The Geissele Stressproof bolt is also forged, not machined from bar stock. This allows us to optimize the grain structure of the steel to yield a bolt capable of 5 times the life of a mil-spec bolt. Each bolt is rigorously inspected, high pressure tested, mag particle inspected and Nanoweapon coated.

Nanoweapon coated, and requires less oil.

The Super Duty upper also includes the  Airborne Charging Handle in black.  The Mk16 rail is unique to this upper, as it has the dovetail fit to the upper.  This is not a standard Geissele Mk16 rail, nor is the upper a standard Geissele upper.  The two are meant to be used as one system.

Note:  Geissele has, over the years, used a number of forgings for their upper receivers, as well as a number of different flash hiders.  The Mod 1 features the mid-length gas, the reinforced QD slot on the rail, and a change to a HUXWRX flash hider, which is pinned and welded in place. 

At Charlie's we offer discounts on key suppressors and optics when purchased with a factory upper or rifle, so be sure to ask.

The Super Duty Complete Upper from Geissele Automatics offers unmatched performance, accuracy and reliability.

Note:  Geissele Black is a special black color.  It is anodized black, but unlike most black rifle, this has a certain very refined look to the finish.  It is not dull like a standard milspec anodizing.

This is a new in the box factory direct upper receiver group model 08-547B.  

Pics courtesy of Geissele


LENGTH:  14.5", pinned and welded to 16.0"
COLOR:  Black proprietary black anodized
RECEIVER:  Geissele Super Duty Upper w/ dovetail cut-out (only fits Geissele Mk16 dovetail rail)
BOLT CARRIER GROUP:         Geissele Nanoweapon Reliability Enhanced BCG 
BOLT:  HPI/MPI Carpenter Steel high impact bolt, either Mil-Spec of Geissele
RAIL:  13.5" SMR MK16 with receiver dove-tail
BARREL:  14.5" Geissele Barrel, CHF, Chrome Lined, 1-7 Twist, phosphated exterior treated
GAS SYSTEM:  mid-length system
GAS BLOCK:  Geissele Super Compact Gas Block - bombproof installation
CHARGING HANDLE:  Airborne Charging Handle - Black

 HUXWRX 556 flash hider DLC Nanocoated